The atmosphere examples directory was empty and untracked, so it never did
anything. The validation .gitkeep files were redundant once their
directories held real content, and data/tle was described as holding TLE
samples that no script reads. Remove all three and correct the README.
The network layer was the only layer without a Python cross-check, and
validation/python/constellation/ was an empty placeholder that the README
described as existing. Add the dump example and the reference script, which
recomputes the geometry from the spherical triangle relations rather than
from the Rust code, and remove the placeholder.
ApsisRS contributors